Fernando I of Leon

Fernando "the Great" of Leon (1017-24 December 1065) was the King of Leon from 1037 to 1065, succeeding Bermudo III of Leon and preceding Alfonso VI of Leon, and king of Castile from 1037 to 1065, succeeding Count Garcia Sanchez of Castile and preceding Sancho II of Castile.

Biography
Fernando Jimena was born in 1017 to Sancho III of Navarre and Mayor of Castile. Fernando was nominated by his father as the successor to his uncle, Count Garcia Sanchez of Castile, who was assassinated in 1029. Fernando became the new Count of Castile, and he married Garcia's intended bride Sancha of Leon in 1032. He became a vassal of King Bermudo III of Leon, but on 4 September 1037 he defeated and killed his suzerain at the Battle of Tamaron, and he became the new King of Leon, succeeding his former liege. Fernando also proclaimed himself the King of Castile, founding the kingdom and abolishing the county. Fernando reigned as the "Emperor of Spain" from 1056 onwards, and in 1060 he fought with the tarifa of Zaragoza and enforced their tribute towards him until his death. He also fought the Emirate of Toledo, defeating Yahya ibn Ismail al-Mamun and forcing him to also pay tribute. He also raided the Taifa of Seville and Tarifa of Badajoz, and he conquered Coimbra in 1064 after a six-month siege. In 1065 he embarked on his last siege, besieging Valencia. With a Muslim alliance with Toledo, he let the Toledans conquer Valencia, as he fell ill and had to return home. Fernando died that same year, and his son Alfonso succeeded him.